Joist stilts for loft boarding

traineepensioner

"Anyone care to take a stab at annual savings to complete the calcs?"

From the people selling the stilts..... "Upgrading your insulation from 75mm to 250mm thick could reduce your heating bills by around £35-75 per year depending on the size of the property."

So, at an average of £50 per year, £695/50...You should break even in 14 years or so
However, the rate at which energy prices are rising it could be a lot sooner. :beer:

martinthebandit

fwor wrote: »

No, I meant that I had looked at adding further cross-joists and boarding on top of that - I had already ruled out stilts as being (IMO) too unstable. The problem is that substantial timber for joists is very expensive.

Hmmm you do know that you do not need substantial timber for cross joists in the loft, in fact, as they are going to be the only thing pressing down into the insulation the thinner the better.

I would be looking at using something 1" wide by however much depth you need so as not to compress the insulation too much.

googler

martinthebandit wrote: »

Hmmm you do know that you do not need substantial timber for cross joists in the loft, in fact, as they are going to be the only thing pressing down into the insulation the thinner the better.

I would be looking at using something 1" wide by however much depth you need so as not to compress the insulation too much.

Surely you lay the first layer insulation between the original joists, install the cross joists and lay the second layer of insulation between them so that it's not compressed?

Probably not practical for the OP, who'll get his free insulation then install boards later, but that's the way it should go, surely....?

googler

traineepensioner wrote: »

"Anyone care to take a stab at annual savings to complete the calcs?"

From the people selling the stilts..... "Upgrading your insulation from 75mm to 250mm thick could reduce your heating bills by around £35-75 per year depending on the size of the property."

We saved around £250 per year by leaving the CH boiler running 24/7, rather than on for short sessions in the morning and evening (i.e the house never goes totally cold, so the CH system doesn't have to work to raise the temp each time it kicks in, only maintain it), so savings in 'only' double figures seem unimpressive......

martinthebandit

googler wrote: »

Surely you lay the first layer insulation between the original joists, install the cross joists and lay the second layer of insulation between them so that it's not compressed?

Probably not practical for the OP, who'll get his free insulation then install boards later, but that's the way it should go, surely....?

I had assumed his insulation would already be fitted.

fwor

martinthebandit wrote: »

Hmmm you do know that you do not need substantial timber for cross joists in the loft, in fact, as they are going to be the only thing pressing down into the insulation the thinner the better.

I would be looking at using something 1" wide by however much depth you need so as not to compress the insulation too much.

Well Ok - my current joists are 4x2" - which means I can only get 100mm of depth when boarded. If I add a cross-layer of joists of 4x1", I would still be short of the recommended thickness of 250mm - and how much would it cost for enough 4x1" timber to cover a 70 sq m roof?

I confess I've not even bothered to calculate with any accuracy, but I'll bet it's a big enough sum to make a theoretical £35-75 a year saving pretty irrelevant.

martinthebandit

Ok, what about this or similar then?

http://www.knaufinsulation.co.uk/press_releases/deck_it_out_with_knauf_insulat.aspx

Happy-Days_3

If you are doing it to save cash on heating, just buy the insulation roll it out in the opposite direction and job done. £30 and that will be repaid in year 1.

If you are doing it to get storage space - it ain't a big moneysaver. But you get the storage. If you want this, buy a load of 2x4, cross baten, then fill those gaps too. Then board. Not quite the 25cm, but better than the 10cm you will get if you just board.

In my profile, link to my blog. Back in Nov I did exactly this, few pics show what I did....

wiggers

Has anyone tried StoreFloor?
http://www.loftzone.co.uk/

verydeeppockets

Loft stilts? I thought that was a wind-up. My god they look unstable.
If you really want cheapness, get 2x3 scant - about £1/m.
Two 'layers' of timber would give you 150mm extra height - and the bottom layer doesn't need to be continuous.